We're in a similar situation with my 3 yo....generally when bubs are getting ready to drop their nap, they will make up for it in nighttime sleep. At 3, the average sleep in 24 hrs is 12 - split between a nap of just over an hour, and a night just under 11. At 2, it's about 13 hrs total. So he'd be somewhere in between. If he's generally been on the high end of sleep, it would be unusual for him to be dropping the nap now, and not making up for it overnight.
I would keep offering it and see if things sort out on their own, or if you notice that he seems OT or not. Have you tried moving around the nap time at all?